Infertility is a common disease in obstetrics and gynecology, it is a specific reproductive health defect and one of the current topics in the field of reproductive medicine, which can have a greater impact on families and society because of the coexistence of physical and psychological factors. Medical surveys and analyses show that the incidence of infertility has been increasing significantly in recent years. In some developed countries, one out of every six couples is infertile, which is related to late marriage, late childbearing, abortion before marriage or unplanned pregnancy, and sexually transmitted diseases. Infertility is related to both men and women, and the following is a brief introduction to the causes, diagnosis and treatment of female infertility. Infertility is defined in China as failure to conceive after two years of marriage without contraception. In healthy young couples with a regular sex life, the chance of pregnancy is only 25-30% per menstrual cycle. According to statistics, 80% of couples are able to obtain a pregnancy through unplanned sex within a year, and another 10% will become pregnant within the second year. Therefore, according to the current situation of late marriage and late childbirth in China, it is recommended that for those who marry late, infertility should be noticed and actively examined and treated after one year of marriage. Infertility is classified into male infertility and female infertility according to the cause of infertility. In women, there is a difference between infertility and infertility. Infertility refers to the failure of a couple of childbearing age to conceive after more than one year of cohabitation and normal sexual intercourse without contraception, either due to an abnormality of the sperm or (and) the egg itself, a disorder of the reproductive tract that prevents the sperm from meeting and uniting with the egg, or due to a disorder of implantation. Infertility is the actual or clinical failure to have a child, i.e., a pregnancy that has ended in miscarriage, preterm delivery, stillbirth or stillbirth, and never a live baby: i.e., an embryo that has implanted and developed to some degree, but cannot be born alive because of impaired growth or delivery of the embryo or fetus. Primary infertility is defined as a couple that has been exposed to the possibility of pregnancy (desire for pregnancy, no contraception, normal sexual intercourse) for 1 year or more without pregnancy. Secondary infertility is defined as a pregnancy that has occurred and has been exposed to the possibility of pregnancy for 1 year or more without further pregnancy (amenorrhea during lactation is not included). Absolute infertility and relative infertility are classified according to treatment and prognosis. Absolute infertility refers to congenital or acquired anatomical or functional defects in one of the spouses that cannot be corrected, while relative infertility refers to conception by one of the spouses due to certain factors that may affect conception with appropriate treatment. Causes of infertility Infertility can be caused by a single factor or by multiple factors. In Asia, 34% of infertility cases are caused by female factors, 13% by male factors, 24% by mutual causes and 13% by unknown causes. Therefore, in the treatment of infertility, both men and women should be examined at the same time. The causes of female infertility are summarized as organic lesions, endocrine factors, immune factors and other factors. Organic lesions 1. Vulva and vagina: Partial or complete longitudinal vaginal septum, transverse vaginal septum, oblique septum, congenital absence of vagina, surgical or trauma-induced narrowing of the vulva or vagina, vaginal spasm, etc. can prevent semen from being ejected into the vagina. In addition, various vaginitis can cause infertility due to increased leukocytes engulfing sperm or affecting the viability of sperm. 2. Cervix: such as cervical fibroids or polyps, malformation of the cervix, cervicitis, etc., can prevent sperm from entering the uterine cavity due to narrow deformation of the cervix or inflammation. 3, uterus: unicornuate uterus, bicornuate uterus, uterine longitudinal septum, etc. sometimes cause infertility due to unfavorable embryonic implantation, and uterine fibroids can affect conception due to the location, size and number of fibroids. Uterine adenomyosis makes it difficult to conceive when the lesion invades the myometrium. Acute and chronic endometritis, endometrial polyps, etc. can 4, cause infertility and sterility. 4. fallopian tubes and ovaries: obstruction or incompetence of the fallopian tubes is one of the most common causes of female infertility, accounting for about 1/3 of the causes of female infertility. Ovarian tumors, ovarian endometriosis, ovarian inflammation, etc. cause adhesions between the ovaries and surrounding tissues, which affect the discharge of eggs and thus affect conception. Endocrine factors 1. Polycystic ovary syndrome (PCOS): 13.7% of female infertility endocrine factors, 33.3% of amenorrhea patients, and 90% of ovulatory dysfunction infertility patients. It is mostly seen in young women and is characterized by obesity, hirsutism, menstrual disorders and infertility, with symmetrical polycystic enlargement of the ovaries bilaterally. The etiology of PCOS is not well understood, but the pathogenesis involves hypothalamic pituitary, adrenal gland, insulin resistance, obesity, etc. Local imbalance of ovarian regulation and genetic factors also play a role. High levels of PRL inhibit hypothalamic gonadotropin-releasing hormone (GnRH) pulses, resulting in low pituitary gonadotropin, which affects follicular development and estrogen secretion, and the positive feedback effect of estrogen on luteinizing hormone (LH) and pituitary follicle-stimulating hormone (FSH) is lost. The positive feedback effect of estrogen on luteinizing hormone (LH) and pituitary follicle stimulating hormone (FSH) is lost, causing anovulation or amenorrhea. The clinical manifestations are mainly changes in menstruation, infertility, and may be accompanied by overflow of breast milk. In addition to physiological factors, elevated prolactin can be caused by the following factors: dopamine-depleting or dopamine-blocking drugs, primary hypothyroidism, chronic renal failure or cirrhosis, chest surgery, empty saddle syndrome, adrenal hypofunction, ectopic PRL secretion, and pituitary prolactin tumors. Endometriosis: It is an autoimmune disease caused by immune dysfunction and it is closely related to infertility. Endometriosis accounts for 42.35%-55.7% of infertility diagnosed according to laparoscopy. There are various theories of its pathogenesis: endometrial implantation theory, somatic epithelial metaplasia theory, lymphatic vein dissemination theory, luteinization of unruptured follicles syndrome (LUFS), genetic immunity theory, etc. Luteal insufficiency: In recent years, about 10%-40% of infertility and recurrent miscarriages are due to luteal insufficiency. It may be related to follicular dysplasia and low endometrial progesterone receptors. Other causes of persistent anovulation: hypothalamic amenorrhea such as those caused by psychological and nutritional factors, or by the use of certain drugs that inhibit the hypothalamus (reserpine, chlorpromazine, contraceptives, etc.). Pituitary causes such as Schihan’s syndrome, Simon’s disease, pituitary tumors, empty saddle syndrome, etc. Ovarian causes such as chromosomal abnormalities (Turner’s syndrome), XX simple ovarian dysplasia, 17-alpha hydroxylase deficiency, XY simple gonadal dysplasia, testicular feminization syndrome or congenital androgen insensitivity syndrome, pseudohermaphroditism, premature ovarian failure, etc. Immunological factors With the development of reproductive immunology, immunological factors have been found to play an important role in infertility, mainly anti-sperm antibodies, anti-cardiolipin antibodies, anti-chorionic gonadotropin antibodies and local immune problems of the endometrium itself. Other factors such as mental factors, age, chronic diseases, smoking and alcohol consumption, working environment, nutritional status, etc. Diagnosis of infertility 1. Medical history: Inquire about the patient’s age at marriage, health status, whether the couple live apart, sexual life, what kind of contraceptive measures are used after marriage and when; menstrual history: age at menarche, menstrual cycle, menstrual volume, whether there is dysmenorrhea; past history: whether there is a history of tuberculosis, especially pelvic tuberculosis and other endocrine diseases; family history: whether there is mental illness and genetic diseases. For secondary infertility, we should know the history of miscarriage and delivery, and whether there is any infection, etc. 2. Physical examination: pay attention to the development of secondary sexual characteristics, such as hair distribution, weight, internal and external genital development, and the presence of deformities and inflammatory masses. Chest radiographs should be done to exclude tuberculosis, and thyroid function tests should be done if necessary. If pituitary pathology is suspected, saddle X-ray and prolactin measurement should be done. If adrenal gland disease is suspected, urinary 17-hydroxysteroids, 17-ketosteroids and blood cortisol measurement should be done. Special tests for female infertility: ovulation detection: including basal body temperature measurement, cervical mucus examination, vaginal exfoliation cytology, endometrial examination, etc. 1. Measurement of endocrine hormones: generally radioimmunoassay is used to measure serum pituitary follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), progesterone (P), testosterone (T), prolactin (PRL), etc. The cyclic changes of the first four hormone levels are obvious, with LH and FSH peaks appearing 24 hours before ovulation and E2 peaks 24 hours before the LH peak. p ≥ 9.6 nmol/L indicates ovulation. lH/FSH, T and PRL values are helpful for the diagnosis of PCOS and amenorrheic lactation syndrome. 2, tubal patency test: After the male partner has no abnormalities and the female partner has normal ovarian function, this test can be done, commonly used are tubal lavage, uterine tubal iodine oil imaging, and tubal lavage under B ultrasound. In addition to checking whether the fallopian tubes are open, tubal lavage can also be used to separate mild tubal adhesions. Hysterosalpingography can clarify the site of obstruction, whether the uterus is deformed, whether there are submucosal fibroids, endometrial and tubal tuberculosis, etc. 3.Immunological test: clinically positive anti-sperm antibodies, especially positive anti-sperm antibodies IgA and IgG in female cervical mucus, inactivation of most of the sperm in the post-coital test, and positive in vitro cervical mucus sperm contact test, indicate immune infertility. 4.Hysteroscopy: It can detect intrauterine adhesions, submucosal fibroids, endometrial polyps, uterine malformations, etc. 5.Laparoscopy: if all the above tests are normal, laparoscopy can be done to directly observe the uterus, fallopian tubes and ovaries for any lesions or mucus. It can also be combined with tubal lysis to observe whether the fallopian tubes are patent under direct vision; at the same time, laparoscopy can also observe small endometriosis and give treatment at the same time so as to improve the environment for conception.